Luminous sign



Jan. 6, 1931. A. RAVA I 1,787,595

LUMINOUS S IGN Filed May 6. 1929 @Ven for 14/6 22022 2 82" 736222 Patented Jan. 6, 19 31 v I i V I UNITED STATES PATENT OFFICE ALEXANDER RAVA, OF CHICAGO, ILLINOIS Lummous sr'en' I Application filed ma 6, 1929. Serial No. 360,655.

The purpose of this invention is to prosuch as, for example, the common so-called vide an-improved construction of a luminous neon light tube. And for the purpose of thus sign in which the illumination of the characdirectin the illumination against the edges ters and representations constituting the disof the p ate at all sides thereof, as is necesplayed matter is effected by a luminous tube sary in order toobtain illumination by re- 55 energized by an electric current. It conflection as described, of all parts of the lines sists in the elements and features of condelineated by the grooves in the plate,- struction shown and described as indicated extending as they may in all directions,- in the claims. such luminous tu e is arranged encompass- In the drawin s: ing the entire peripheral edge of the plate.

Figure 1 is a Front elevation of a display In order that the characters delineated in device embodying this invention, the plate and illuminated as described may Figure 2- is an elevation of a transparent not be rendered inconspicuous by the possiplate comprised in the device bearing the disb y greater brilliancy of the encompassing play characters. illuminating tube, and in order also to pro- 5 Figure 3 is a section at the line 3-3 on tect the tube, the latter is enclosed on all Figure 2. sides except the side toward the edge of the Figure 4 is a section at the line 4-4 on plate, by a suitable opaque housing which is Figure 1. made highly reflective by silvering or paint- Figure 5 is a front elevation of the device ing white in order to conserve the light of the of Figure 1 with the display plate removed luminous tube and concentrate it to the edge and a plate-retaining skeleton door swung of the transparent plate. This housing also to open position. serves conveniently as a frame for the plate,

Figure '6 is a section in a plane parallel to into which the latter may be inserted and 25 the face of the display plate of the device from which it may be removed without deshown in Figure 1, including the display stroying or exposing to injury the illuminatplate in position therein. ing tube or interrupting the energizing cir- The invention consists in the delineation cuit. And the construction has the further in one face of a transparent plate of the advantage that a plurality of transparent 30 characters and figures which are to constiplates of'the same dimensions and contour tute the display, such delineation being by may be interchangeably employed in the same angular grooves in the plate, the sides of frame encompassed by the same undisturbed which are sloped obliquely to the face of the luminous tube, the interchange being effectplate at an angle which is substantially the ed as readily as signs arranged to be suspendA angle of total reflection of the particular maed on the same hook may be interchanged terial of which the plate is made, and in obwith each other.

taining illumination of the lines of said dc- Referring more particularly to the drawlineated characters by light directed edgeings: A is a frame or casing having a closed wisev into the plate so as to encounter the back of opaque material, indicated at 10, and

40 oblique slopes of the character lines at the an apertured front wall of opaque material angle of total reflection, causing the light to indicated at 11. The aperture, 12, being conbe reflected directly through and at right formed in contour to the contour of-the transangles to the face of the plate opposite that parent plate, or interchangeable plates, proin which the grooves are formed. vided for insertion therein as described, hav- 4 The means employed for directing illumiing the characters constituting the display nation edgewise into the transparent plate delineated by grooves in the rear or inner consists of an electrically energized luminous face of the plate as described.

tube, that is, a tube occupied by a suitable In the frame or casing justback of the margas adapted to become luminous upon the gin of the aperture, 12, and encompassing the passage of an electric current through. it, position of the transparent plate when the latter is mounted in the aperture as mentioned, there is mounted on suitably distributed supports seen at 14, the luminous tube indicated at C, having inleading and outleading electrical connections indicated at 15 and 16 respectively.

For retaining the plate, E, safely in position in the casing and encompassed by the luminous tube, there is provided a skeleton door, D, dimensioned for lapping in front of the margin of the plate encompassing the aperture, 12, and lapping also the margin of the aperture andfthereby lapping the margin ofthe plate lodged in the aperture of the easing, said skeleton door being desirably hinged at the lower side of the front plate of the frame and provided with a catch, 17, f or holding it at closed position. lapping the margin of the plate as mentioned, and retaining said plate in position for being illuminated by the encompassing luminous tube, C.

It will be understood that the color in which any groove line of the plate will be illuminated will be determined by the color of the light emitted from the portion of the luminous tube extending at the portion of the edge of the plate through which the light enters for reflection from the proximate slope of the groove; and accordingly it will be understood that by making diflerent portions of the encompassing tube, C, of different col-- 1 And in Figure 2 the ors, or so that the light emitted through the tube from the luminous gas within, in view of the color presented by the particular gas used in the tube when rendered incandescent by the energizing current, shall be different at the different portions of the tube, different lines of the several characters will be illuminated in different colors. And, for example, by making the tube at the opposite side edges of the plate to emit light of complimentary colors, as red and green respectively, the groove lines running transversely to the direction of the rays reaching the oppositely sloped sides of the grooves will be displayed each in two colors, which maybe complimentary for brilliancy of effect. That is, each such line will present two colors in parallel. And similarly, by making the portions of the tube which extend along the upper and lower edges of the plate at the right hand half of the length of the plate of one'color, and the portions extending along the left hand half of the plate of a different color, the two portions of the sign will be displayed in the two different colors.

Such variations of color are indicated in the drawings by the conventional surface markings for different colors, the right hand portion of the sign in Figure 1 being represented as illuminated in red, the left hand portion represented as illuminated in green. vertical lines of letters are represented as double, half red and half green, in parallel.

I wish itunderstood that my invention is not limited to any particular transparent material, or to having any particular angle of total reflection 3 and while in the drawings I have shown the grooves as right angular, which presumes on the employment of a transparent medium whose angle of total reflection is approximately 45, which is substantially the angle of total reflection of some grades of glass, other sorts of glass or other transparent material having a greater or less angle of total reflection may be employed with substantially equal effectiveness.

It will be observed upon consideration that by this method the length of luminous tube required. for a given sign being only the length necessary to encompass the sign as an entirety, will almost always be very much less than would be necessary to form the sign in the customary manner, that is, with a continuous luminous tube flexed to follow the course of the lights constituting the characters of the sign or other display.

It will also be observed that this method of illumination imposes no limitation upon the form of the letters or characters such as is imposed by the necessity of flexing the luminous tube, so that its continuity from beginning to end of the entire inscription or other delineation constituting the display is not interrupted, this requirement, it will berecognized, making it practically impossible or very difiicult to delineate certain words and phrases by the method of a continuous luminous tube forming all the letters of all characters. By the method above described, on the contrary, thesign may be first designed in any form desired, and then delineated in the grooves; and thereupon, by encompassing the body of the plate by a luminous tube, all the lights of the sign tobe displayed become luminous by reflection.

Although I have shown a plain or flattened glass as the transparent plate, I wish it understood that the invention is not thus limited and that other forms beside perfectly flat plates may be used with the marks engraved or molded by grooves having oppositely sloped sides and illuminated through the edges of the glass, with very pleasing effects, all within the scope and intent of my invention.

I claim:

. 1. A luminous sign consisting of a transparent plate having the. characters to be luminously displayed formed by grooves in the face of the plate, said grooves having their sides sloped at an angle to the face of the plate opposite that in which they are formed which is substantially the angle of total reflection of the particular material of the plate, and a luminous tube mounted to extend along opposite side edges of the plate;

the plate opposite that in which they are formed which is substantiallythe angle of total reflection of the particular material of the plate, and a luminous tube mqunted to extend respectively along opposite side edges of the plate; whereby the light projected from the plate edgewise thereof is re flected from the slopes of the grooves forwardly from the plane of the face of the plate opposite that in which the grooves are formed, said luminous tube portions being constructed for admitting light of different i of the plate, and a luminous tube encompasscolors at the opposite side edges of the plate, whereby the character lines each comprise two colors in parallel.

3., A luminous sign consisting of a transparent plate having the characters to be luminously displayed formed by grooves whose sides are sloped at an angle to the face of the plate opposite that in which theyare formed which is substantially the anglejof total reflection of the particular material ing the peripheral edge of the plate, said tube being constructed for admitting light of different colors at different parts of its plateencompassing extent.

4. A luminous sign consisting of a transverse plate having the characters tobe luminously displayed formed by grooves whose opposite sides are sloped atan angle to the face of the plate opposite that in which they are formed, which is substantially the an le of total reflection of the particular material of which the plate is formed, and a luminous tube'encompassing the peripheral edge of the plate, said tube being constructed for admitting light of different colors at opposite side edges of the plate.

5. A luminous sign consisting of a transparent plate having the characters to be luminously displayed formed by grooves in the face of the plate whose sides are sloped at an angle to the face opposite that in which the groovesare formed which is substantially the angle of total reflection of the particular material of the plate, and a luminous tube mounted to extend along the edge of the plate, whereby the light projected into the plate edgewise thereof is projected onto the slopes of the character grooves forwardly from the plate of the face opposite that'in which the grooves are formed. a frame for the transparent plate comprising a housingtransparent plate and closed at the remaining sides, said frame coinprislng a closure plate extending over the entire area encompassed by the housing at the grooved side of the transparent plate, and having a skeleton plate-retaining member for retaining the transparent plate in tube-encompassed position, and means for removably holding said skeleton member to the housing in position for retaining the transparentplate in said encompassed position.

6-' A luminous sign consisting of a transparent plate having the characters to be luminously displayed formed by grooves in the face of the plate. whose sides are sloped at an angle to the face opposite that in which the grooves are formed which is substantially the angle of total reflection of the particular material of the plate, and a luminous 1 tube mounted to extend along the edge of the plate, whereby the light projected into the plate edgewise'thereof is projected onto the slopes of the character grooves forwardly from the plate of the face opposite that in which the grooves are formed, a housing fo the luminous tube enclosing the same on all sides except the side toward the edge of the transparent plate and open at that side, said housing having its interior surface rendered highly reflective to avoid absorption of the light of the luminous tube and increase the light emitted through the open side toward the edge of the plate.

7 A luminous sign consisting of a transparent. plate having .the characters to be luminously displayed formed by grooves in the face of the plate whose sides are sloped at an angle tothe face opposite that in which the grooves are formed which is substantially the angle of total reflection of the particular material of the plate, and a luminous tube mounted to extend along the edge of the plate, whereby the light projected into the plate ioo edgewise thereof is projected onto the slopes of the character grooves forwardly from the plate of the face opposite'that in which the A grooves are formed, a frame structure for housing and protecting the luminous tube having at the side opposite the grooved face of the plate an opening dimensioned for ad- -mitting theplate to the position at which it ly the angle of total reflection of the particular material of the I slate, and a luminous tube mounted to exten along the edge of the plate, whereby the light projected into the plate edgewise thereof is pro ected onto the slopes of the character grooves forwardly from the plate of the face opposite that in 5 which the grooves are formed, a frame structure for housing and protecting the luminous tube having at the side opposite the grooved face of the plate an opening dimensioned for admitting the plate to the position at which it is encompassed by the luminous tube, and

a skeleton retaining member movably attached to the frame structure apertured for exposing the illuminated area of the plate and lapping the margin of the plate for re- :aining it safely in tube-encompassed posi- In testimony whereof, I have hereunto set my hand at Chicago, Illinois, this 2d day of May, 1929.

ALEXANDER RAVA. 

